Water tube boiler construction



June 9, 1931.- K. L. MARTIN WATER TUBE BOILER CONSTRUCTION Filed NOV. 29, 1929 INVENTOR Patehteilluhe 1,809,133

WATER, TUBE BOILER; consrRuorIo '11 Application filed novem erizale sa .;.seria151vo.410,423? {f The invention relates to steam boilers ofgnectedgto the longitudinal Ldr um 7 by s'hort the water tube type andmore particularly to nippless, andthe,downtake-headers bylong fthose having'straight tubes inclined some-flnipples 9lijln icertain forms of boilers, a

what from the horizontal with waterrcom: across-drum is used and a difi'erentfmthod c 6 partments at their ends and a steam and wa. rof/connecting the headers is used but thisisjm ter drum above the tubes. Dificulty has beengnot -material to my invention 1 I experienced in baffling boilers of this typefflfThei bafiie.construction icomprises four in such a manner as to secure complete com H parts; first, alower horizontal baffle 10, which bustion and avoid the production of heavy I; may be laid on one of the twolower rows of 10 smoke with certain grades of coal. One tubes,but preferably surrounds thelowerrow 60' method of baffling employed involves the use of tubes so' as to form a icontinuousiifrac c of a plurality of horizontalbaifles. This sys-f; itoryrooflforfthefurnace. Second, a" lower tem is open to the objection that. dead spaces f crossbaflle 11 preferably inclined toward the are formed where little or no gas passes over nearest-header5,; {This inclinatioiilztendsto 15 the heating surface of the tubes. The movepreventthe accumulationfl of soot 'and slagg 65 v Another method of bafiling permits the gases gth'eheat transferiare at the maximum. v c

v ment of the gases longitudinally of tubes has decreases the enteringy'eloci-tyfof the; gases, 7

also been found-to involve a relatively lower maintains substantially uniform velocity of degree of heat transfer than that: present flow; and'for ces the gasesfacross the tubeso a i, when the'gases flow transversely of the tubes. I that the scrubbinglaetion' ofthe gases and from the furnace topass up directly complete Third; anfupp'er eross bafll 12 also 'prefer c r 1y through thebank of tubes where'the'y ar'ei ably inc'line'd and nearlypa'rallelto the lower reversed and made to fiow'down throughthe l cross baifief islused to directt the gases down- 1 tubes followed by .a second reversal and ayfard across the tubesforming'asecondpass i v flow upward again through the tubes. This: after;.reversal;. inthe 'lower'partjof the 1 the tubes before combustion iscompleted. My I} p I invention is designed to' combine the best ifprferably on the topirow of tubes to pre so; p

I i drawinfgl, wherein;

method, while efficient, produces heavy smoke; tube space belowthebafilejm, the gases again v particularly with fuels of high volatile conjerossthe; ubes' in the'thir d passtand flow to 7 tent, as the gas enter the cool spaces between' the outlet -of theiboilerf 14. I Y i amie is laid l r a 1 5a uppe rh o b features ofthe methods heretofore used an empura;gases;wm areascendin the first to overcome the objections togsuch methods' passffrom goingdirectly to the boilerg out' letas above pointed out. One form of the in 14;; directing 'them, instead downwardlyinto vention is illustratedin the accompanying, the second' pass l i v f V 1 I l. If' 'a tricted space betweeni the jsteam S The ure is a longitudinal section part-drum or'dr'ums make 'it advisable to lay the ly in side elevation of a'steam boiler embodyupper horizontalbafile lf on other than the I ing the inventiona t p r mixe -en be i fadil id n with it Re r g w to t r w g s h fr nt affectin the *arr'angementshown otherwise i 40 wall and 2 is the bridge wall of afurna'ce the than to'. shorten by a corresponding amount;

4 shown at 4:, or may be su'bdivided into upper usual types may be located in the space be upper portionof the combustion chamber of the -1 wer*@r0'ss ba-flle"11,if'necessary, to prowhich is indicated at 3. The water tubes vide adequate area between'thefirst and sec of a horizontal watertube boiler are located ond passes. v v 7 c 7 I above the furnace and may be in one group as c A superheaterQ-not shown, of any of thel and lower groups; but the grouping of the tween the upper baffle 13 and the steam drum tubes is not materi l o my invention. The "7, or it'may' be located in the bank of tubes tubes are connected at one end to do-wntake by omitting, any desired numberof tubes to headers 5, and at the otherend to uptake make room for it. i

headers 6; The uptake headers are .Qcon- It will be seen that by 'plac'ingtheilowe J baffle- 10 on the lower row of tubes, a refractory roof is formed which is highly heated by the radiant heat from the fuel and by contact with the hot gases of combustion, and this heat is partly transmitted to the adj acent tubes but largely reflected back into the burning'gases materially aiding in completing combustion before the entrance to the first pass is reached. i

' wide throat is provided by the inclined.v 7 baffle 11 insuring low'entering velocity and freedom from slag trouble. :The cross baf-v fies direct the gasesacross the tubes three times, alldead spaces are eliminated anda.

' 15 maximum rate of heat transfer is maintained.

' Asu'bstantially uniform gas velocity can be e l maintained {bY' properly proportioning the areaof the-gas passages to compensate for the shrinkage of the gases as they cool. This" will tend to'keep soot and ash in suspension I untilthe expansion of the gases in the enlarged space above the top bafiie 13, will slow thevelocity, and suspended matter will deposit onitop of bafiie 13, whence it canbe as readily removed. v I 1 'By the arrangement shown, the maximum efficiency as shown by low, flue gas tempera tureslfand the maximum capacity with the v- T lowest draft loss from the furnace 3-t0 the boiler outlet 14, isobtained. a VVhatIclaim is: g In a boiler of thewater tube type having.

f a furnace at thefront end and comprising a bankfof tubes inclined from front to rear, upright headers at the ends of the tubes and a steam and water drum above the headers with i which they communicate, a combustion chamber below the forward end of the boiler with r r p a bridge wall at its rear end, a baffle around the lower rowof tubes extending rearward from the front header a part of the length of the tubes anditerminating directly above thebridge wall, across baflie extending upf Iwa'rd and to the rear fromthe end of the battle at an obtuse angle to such bafile, a third V baflie on 'oneof the upper rows of tubes exa tending fronnthe rear'header forwardly a part of the length of the tubes, and a cross baflie extending downward'from the end of ,;said la'st'baffle at an obtuse angle to such 1 bafiie; 7' V y i In testimony whereof, I have hereunto subscribed my name this 25th day of November, 1929.

I KINGSLE'Y L. MARTIN. 

